# cellStats: Statistics across cells In raster: Geographic Data Analysis and Modeling

## Description

Compute statistics for the cells of each layer of a Raster* object. In the `raster` package, functions such as max, min, and mean, when used with Raster* objects as argument, return a new Raster* object (with a value computed for each cell). In contrast, cellStats returns a single value, computed from the all the values of a layer. Also see `layerStats`

## Usage

 ```1 2 3 4 5``` ```## S4 method for signature 'RasterLayer' cellStats(x, stat='mean', na.rm=TRUE, asSample=TRUE, ...) ## S4 method for signature 'RasterStackBrick' cellStats(x, stat='mean', na.rm=TRUE, asSample=TRUE, ...) ```

## Arguments

 `x` Raster* object `stat` The function to be applied. See Details `na.rm` Logical. Should `NA` values be removed? `asSample` Logical. Only relevant for `stat=sd` in which case, if `TRUE`, the standard deviation for a sample (denominator is `n-1`) is computed, rather than for the population (denominator is `n`) `...` Additional arguments

## Details

`cellStats` will fail (gracefully) for very large Raster* objects except for a number of known functions: sum, mean, min, max, sd, 'skew' and 'rms'. 'skew' (skewness) and 'rms' (Root Mean Square) must be supplied as a character value (with quotes), the other known functions may be supplied with or without quotes. For other functions you could perhaps use a sample of the RasterLayer that can be held in memory (see `sampleRegular` )

## Value

Numeric

`freq`, `quantile`, `minValue`, `maxValue`, `setMinMax`

## Examples

 ```1 2 3 4 5 6 7 8``` ```r <- raster(nrow=18, ncol=36) values(r) <- runif(ncell(r)) * 10 # works for large files cellStats(r, 'mean') # same, but does not work for very large files cellStats(r, mean) # multi-layer object cellStats(brick(r,r), mean) ```

### Example output

```Loading required package: sp
 4.807896
 4.807896
layer.1  layer.2
4.807896 4.807896
```

raster documentation built on Jan. 23, 2022, 1:08 a.m.